Support ARDUINO_CONFIG environment variable

[weshouman]

Describe the request

Is it possible to support setting the configuration file using an environment variable?

Currently it's possible to set the config file through multiple ways, like --config-file and by auto checking the current and parent directories. However, using an environment variable to ensure all the upcoming commands will be using the correct config file would ensure consistency and confidence in the result.

Note, as a current workaround, I'm shadowing the arduino-cli command using the following bash function, which indeed works, but it's not a clean solution.

arduino-cli() {
    if [ -n "$ARDUINO_CONFIG" ]; then
        # ARDUINO_CONFIG is set, use it with --config-file
        command arduino-cli --config-file "${ARDUINO_CONFIG}" "$@"
    else
        # ARDUINO_CONFIG is not set, call arduino-cli normally
        command arduino-cli "$@"
    fi
}

Describe the current behavior

No environment variable are mentioned in the documentation that would set the --config-file

Arduino CLI version

Version: 0.34.2

Operating system

Linux

Operating system version

Any

Additional context

No response

Issue checklist

• I searched for previous requests in the issue tracker
• I verified the feature was still missing when using the nightly build
• My request contains all necessary details

[alessio-perugini]

👋 We currently support something similar via ARDUINO_DIRECTORIES_DATA. When that env var is set the cli will search for arduino-cli.yaml in the path specified by that env. (if you're curious here is the snippet).

[weshouman]

This actually works.

However, I've just rechecked my use case, and I do have multiple configuration files in the same directory, each with a different name, thus this solution of specifying a directory for the arduino-cli.yaml does not allow arbitrary configuration file naming as allowed by --config-file

[alessio-perugini]

Ok, we can add that.
Implementation notes:

• add env name: ARDUINO_CONFIG_FILE
• add doc

[alessio-perugini]

Will be shipped in the v0.36.0 or directly in the v1.0.0-rc.1